Indutherm MC60V - Page 44

System
description
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2019-01-08
4–27
Rough Surfaces
Figure 24: rough surfaces
Cause
Remedy
 Rough waxes.
 Use less release agent on the rubbers.
This can be caused by excess of tal-
cum. Use only a trace of talcum. Never
use silicon spray.
 De-wax temperature too hot.
 Do not exceed 150 ºC during de-wax.
 Steam de-waxed for too long.
 Steam, de-wax for a maximum of 1
hour. Steam will erode surface of the in-
vestment.
 De-waxed too quickly.
 Leave flask for at least 1 hour to
achieve maximum strength before de-
waxing.
 Flasks overheated during burn out.
 Ensure maximum burn out temperature
does not exceed 730 ºC.
 Metal too hot.
 Reduce casting temperature.
Inclusions
Figure 25: inclusions
Cause
Remedy
 Improper sprues.
 Eliminate sharp corners in sprue system.
 Crucible break down.
 Replace crucible. Do not used old, disintegrating cruci-
bles.
 Dirty metal.
 Do not use more than 50 % recycled alloy and ensure it
is clean.
 Flasks overheated dur-
ing burn out.
 Ensure maximum burn out temperature does not ex-
ceed 730 ºC.